Photochromic materials having electron-withdrawing substituents
US7556751B2 · kind B2 · utility
5Cited by
10References
25Claims
0Family size
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Key dates
| Filing date | Dec 21, 2005 |
| Grant date | Jul 7, 2009 |
| Priority date | — |
| Expiry date | Jan 10, 2027 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K2211/1088
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Photochromic materials comprising indeno-fused naphthopyrans having a first electron-withdrawing substituent and, in certain non-limiting embodiments, a second electron-withdrawing substituent are disclosed. The photochromic materials according to the various embodiments may display faster fade rates, bathochromic shift, and higher performance ratings compared to comparable indeno-fused naphthopyrans without the electron-withdrawing substituents. Photochromic compositions and articles, such as optical elements, incorporating the photochromic materials are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.